The Equine Water Treadmill: What is the Evidence?

 

With the popularity and availability of the equine water treadmill growing globally, it is worth taking a moment to look at the research available (so far) for this modality, and at established protocols or standards of practice that ensure the safety of horse and handler.  

 

A great deal of research has been conducted on the use of the water treadmill, with results showing improved joint range of motion in the limbs, changes in kinematics of the back, improved postural stability of horses with arthritis, and much more. Nonetheless, significant gaps in the evidence remain, especially when it comes to the use of the water treadmill for the rehabilitation of specific conditions.

 

If you watched our research refresh in the Onlinepethealth Equine members portal ‘Consensus for the General Use of the Equine Water Treadmill in Healthy Horses’, you will have gained some valuable insight on the recommended protocols for the safe use of this modality. In today’s blog, I would love to dive into the insights gained from additional research. 

 

Where we are today

Equine water treadmills are becoming increasingly common and popular, both for conditioning the equine athlete and for rehabilitation purposes.

There are multiple designs of water treadmills, but most allow for a change in water depth and belt speed, while some also allow the use of an incline. When creating treadmill protocols for an individual patient, we need to consider the following variables:

• frequency of exercise
• duration of exercise
• water depth
• belt speed
• the use of additional training aids and tools.

There seems to be a huge variety of treatment programmes or protocols among users, even for patients with the same rehabilitation or training goals (Tranquille et al., 2018). This highlights the need for guidelines to be established on best practice.

In 2019, a working group of researchers, academics, experienced water treadmill users, veterinarians and veterinary physiotherapists was formed, with the purpose of discussing and compiling a set of protocols and practices to be used as a guideline for general use of the equine water treadmill.

 

Guidelines for best practice in the use of the equine water treadmill

The guidelines created include information on the following areas:

1. General good practice in water treadmill exercise
2. Introduction of horses to the water treadmill
3. Factors influencing the selection of speed, water depth and duration
4. Monitoring movement on the water treadmill
5. Optimal use of the water treadmill in a training or rehabilitation programme.

You can view and download the detailed protocols on the Onlinepethealth Equine members portal, or download the full article from the journal, Animals.

The evidence available on equine water treadmill use

Below is a summary of the research we have available so far on the equine water treadmill.

International survey of equine water treadmills—why, when, and how? Tranquille, C., Tacey, J.B., Walker, V.A., Nankervis, K., Murray, R.C. J. Equine Vet. Sci. 2018, 69, 34–42.

Effects reported: The water treadmill is being used increasingly in cross-training programmes for equine athletes, as well as in rehabilitation programmes. There are significant differences among venues for water treadmill protocols.

 

Conditioning equine athletes on water treadmills significantly improves peak oxygen consumption, Greco-Otto, P., Bond, S., Sides, R., Bayly, W. & Leguillette, R. Vet. Rec. 2020, 186, 250.

Effects reported: Improved aerobic capacity by 16% after 18 days of exercise.

 

Effect of water depth on amount of flexion and extension of joints of the distal aspects of the limbs in healthy horses walking on an underwater treadmill, Mendez-Angulo, J.L., Firshman, A.M., Groschen, D.M., Kieffer, P.J. & Trumble, T.N. Am. J. Vet. Res. 2013, 74, 557–566.

Effects reported: Increased joint ROM in the lower limb joints, especially flexion. Water depth affected which joints had the greatest increases in flexion.

 

Water height modifies forelimb kinematics of horses during water treadmill exercise, McCrae, P., Bradley, M., Rolian, C. & Léguillette, R. Comp. Exerc. Physiol. 2021, 17, 91–98.

Effects reported: In water, stride length increased, stride frequency decreased, and an increased swing phase percentage of the stride was measured. 

 

Biomechanical responses of the back of riding horses to water treadmill exercise, Mooij, M., Jans, W., Heijer, G.D., De Pater, M. & Back, W. Vet. J. 2013, 198, e120–e123.

Effects reported: Increasing water depths caused an increase in axial rotation and flexion of the spine, with more lateral bending occurring after ten days.

 

Water depth modifies back kinematics of horses during water treadmill exercise, Nankervis, K., Finney, P. & Launder, L.M. Equine Vet. J. 2015, 48, 732–736.

Effects reported: Higher water depth resulted in cranial thoracic extension and thoracolumbar flexion of the horse’s spine.

 

Effect of underwater treadmill exercise on postural sway in horses with experimentally induced carpal joint osteoarthritis, King, M.R., Haussler, K.K., Kawcak, C.E., McIlwraith, C.W. & Li, R.F.R. Am. J. Vet. Res. 2013, 74, 971–982.

Effects reported: Improved postural stability was evident during various stance position tests, compared to horses exercised on a ground treadmill.

 

Biomechanical and histologic evaluation of the effects of underwater treadmill exercise on horses with experimentally induced osteoarthritis of the middle carpal joint, King, M.R., Haussler, K.K., Kawcak, C.E., McIIwraith, C.W., Reiser, R.F., Frisbie, D.D. & Werpy, N.M. Am. J. Vet. Res. 2017, 78, 558–569.

Effects reported: Improved use of arthritic limbs, improved joint range of motion, and improved synovial membrane integrity.

 

Water treadmill exercise reduces equine limb segmental accelerations and increases shock attenuation, Greco-Otto, P., Baggaley, M., Edwards, W.B. & Leguillette, R. BMC Vet. Res. 2019, 15, 1–10.

Effects reported: Minimised segmental acceleration of the forelimb and decreased impact shock.

 

Effects of aquatic conditioning on cartilage and bone metabolism in young horses. Silvers, B.L., Leatherwood, J.L., Arnold, C.E., Nielsen, B.D., Huseman, C.J., Dominguez, B.J., Glass, K.G., Martinez, R.E., Much, M.L. & Bradbery A.N, J. Anim. Sci. 2020, 98.

Effects reported: 112-day treadmill programme had no negative effects on cartilage metabolism in yearlings.

 

Change in muscle development of horses undergoing 20 weeks of water treadmill exercise compared with control horses, Murray, R.C., Hopkins, E., Tacey, J.B., Nankervis, K.J., Deckers, I., MacKechnie-Guire, R. & Tranquille, C.A. Proceedings of the British Equine Veterinary Association Congress 2020, Birmingham, UK, 9–12 September 2020.

Effects reported: 20 weeks of regular water treadmill exercise led to subjective increases in hindquarter muscle mass compared to a control group.

 

A search on Pubmed for ‘Equine Water Treadmill’ yields 70 results. These include research articles focused on kinematics, blood biochemicals, metabolic responses of muscle groups, cartilage and bone metabolism, young horses, osteoarthritis, EMG muscle activity, heart rate parameters, and more.

While there is research available on this modality, and we have some idea of its effects on the horse and how we might apply the modality to healthy horses, we need a great deal more information on how the equine water treadmill affects horses with soundness challenges and different pathologies before we can confidently use it in the rehabilitation setting.

 

Conclusion

With the increasing availability and use of the equine water treadmill in the training and rehabilitation of equines, the prioritisation of safety and efficacy of use becomes more necessary. By familiarising ourselves with the available literature, contributing to future literature on its use in rehabilitative settings, and continuing to engage in conversations about best practices and safety measures, we can contribute to the value of the equine water treadmill as part of an effective toolkit for equine rehabilitation.

If you enjoyed the above summary and the research articles referred to, and would like your own little reference booklet, why not download our Free Citation Booklet. We have filled in a few of our favourite papers to get you started, and left you with loads of empty pages where you get to fill in your own findings from research articles you read. Filled in in this way, the booklet will provide you with a quick reference guide for when you are chatting to vets, putting together reports or need some inspiration for your social media pages!

 

References

1. Kathryn Nankervis, Carolyne Tranquille, Persephone McCrae, Jessica York, Morgan Lashley, Matthias Baumann, Melissa King, Erin Sykes, Jessica Lambourn, Kerry-Anne Miskimmin, Donna Allen, Evelyne van Mol, Shelley Brooks, Tonya Willingham, Sam Lacey, Vanessa Hardy, Julie Ellis  and Rachel Murray, 2021.  Consensus for the General Use of Equine Water Treadmills for Healthy Horses. Animals 2021, 11, 305.
   
2. Greco-Otto, P., Baggaley, M., Edwards, W.B., Leguillette, R. 2019. Water treadmill exercise reduces equine limb segmental accelerations and increases shock attenuation. BMC Vet. Res. 15, 1–10.
3. Greco-Otto, P., Bond, S., Sides, R., Bayly, W., Leguillette, R. 2020. Conditioning equine athletes on water treadmills significantly improves peak oxygen consumption. Rec. 186, 250.
4. King, M.R., Haussler, K.K., Kawcak, C.E., McIlwraith, C.W., Li, R.F.R. 2013. Effect of underwater treadmill exercise on postural sway in horses with experimentally induced carpal joint osteoarthritis. J. Vet. Res. 74, 971–982.
5. King, M.R., Haussler, K.K., Kawcak, C.E., McIlwraith, C.W., Reiser, R.F., Frisbie, D.D., Werpy, N.M. 2017. Biomechanical and histologic evaluation of the effects of underwater treadmill exercise on horses with experimentally induced osteoarthritis of the middle carpal joint. J. Vet. Res. 78, 558–569.
6. King, M.R. 2016. principles and application of hydrotherapy for equine athletes. Clin. N. Am. Equine Pr. 32, 115–126.
7. McCrae, P., Bradley, M., Rolian, C., Léguillette, R. 2021. Water height modifies forelimb kinematics of horses during water treadmill exercise. Exerc. Physiol. 17, 91–98.
8. Mendez-Angulo, J.L., Firshman, A.M., Groschen, D.M., Kieffer, P.J., Trumble, T.N. 2013. Effect of water depth on amount of flexion and extension of joints of the distal aspects of the limbs in healthy horses walking on an underwater treadmill. J. Vet. Res. 74, 557–566.
9. Mooij, M., Jans, W., Heijer, G.D., De Pater, M., Back, W. 2013. Biomechanical responses of the back of riding horses to water treadmill exercise. J. 198, e120–e123.
10. Muñoz, A., Saitua, A., Becero, M., Castejón-Riber, C., Satué, K., De Medina, A.S., Argüelles, D. 2019. The use of the water treadmill for the rehabilitation of musculoskeletal injuries in the sport horse. Vet. Res. 63, 439–445.
11. Murray, R.C., Hopkins, E., Tacey, J.B., Nankervis, K.J., Deckers, I., MacKechnie-Guire, R., Tranquille, C.A. 2020. Change in muscle development of horses undergoing 20 weeks of water treadmill exercise compared with control horses. In: Proceedings of the British Equine Veterinary Association Congress, Birmingham, UK, 9–12 September 2020.
12. Nankervis, K., Finney, P., Launder, L. 2015. Water depth modifies back kinematics of horses during water treadmill exercise. Equine Vet. J. 48, 732–736.
13. Nankervis, K., Launder, E.J., Murray, R.C. 2017. The use of treadmills within the rehabilitation of horses. Equine Vet. Sci. 53, 108–115.
14. Silvers, B.L., Leatherwood, J.L., Arnold, C.E., Nielsen, B.D., Huseman, C.J., Dominguez, B.J., Glass, K.G., Martinez, R.E., Much, M.L., Bradbery, A.N. 2020. Effects of aquatic conditioning on cartilage and bone metabolism in young horses. Anim. Sci. 98.
15. Tranquille, C., Tacey, J.B., Walker, V.A., Nankervis, K., Murray, R.C. 2018. International Survey of Equine Water Treadmills—Why, When, and How? Equine Vet. Sci. 69, 34–42.